Beyond the Lab and Borders: A Systematic Review of Success, Mental Health, and Career Transitions Among International PhD Students in the United States

Background : International PhD students represent a significant and growing portion of the U.S. doctoral population, particularly in STEM disciplines. Despite their vital contributions to research and innovation, these students face distinct structural and psychosocial challenges that may hinder academic success, mental health, and career outcomes. Methods : We conducted a systematic review of empirical studies published from 2019 to 2025, focusing on international PhD students in U.S. institutions. A convergent synthesis approach was used to integrate quantitative and qualitative data, analyzing outcomes related to academic persistence, psychological well-being, and career transitions. Findings : Thirty-eight studies met inclusion criteria, spanning multiple disciplines and methodological approaches. Key findings revealed high rates of depression, anxiety, and stress; visa-related career uncertainties; delays in degree completion due to unstable funding and ineffective mentorship; strained supervisory relationships; and weak institutional belonging. These challenges were often compounded, reinforcing systemic disadvantages for international doctoral students. Interpretation : The results suggest that individual resilience alone is insufficient to address the multi-layered challenges faced by international PhDs. Institutions and policymakers must implement systemic reforms—such as culturally competent mental health services, visa-informed career advising, and intercultural mentorship training—to foster equity, retention, and long-term success for this essential academic population.